Explanation
Correct answer: D.
Choice D is the best answer because it presents a finding that, if true, would most strongly suggest that positive feedback had the psychological effect Trewick and her team predicted but not the predicted physical effect. The text explains that Trewick and team predicted positive feedback would, in a virtual reality environment, replicate two real-world results: an enhanced psychological experience (higher enjoyment) and improved physical endurance (longer maintenance of target heart and pedaling rates). If participants who received positive feedback reported greater enjoyment than those who received negative or neutral feedback, that would indicate that the predicted psychological effect occurred. At the same time, if those participants maintained their heart and pedaling rates for approximately the same durations as participants in the other groups, that would indicate that the predicted physical effect did not occur, since positive feedback didn’t produce longer maintenance of target heart and pedaling rates. Together, these results would indicate that positive feedback produced the predicted psychological effect but not the predicted physical effect.
Why the other choices are wrong
Choice A
Choice A is incorrect. Reported enjoyment being greater with positive feedback than with neutral feedback would be evidence of the predicted positive effect of positive feedback on participants’ psychological experience, but the fact that participants had greater endurance with neutral feedback than with negative feedback wouldn’t reveal anything about how endurance was affected by positive feedback, and thus wouldn’t show that positive feedback didn’t have the predicted physical effect.
Choice B
Choice B is incorrect. A finding that participants who received negative feedback reported lower enjoyment than participants who received positive or neutral feedback did would show that enjoyment was lowered by negative feedback but wouldn’t confirm that enjoyment was greater with positive feedback than with neutral feedback, which a finding would need to do to demonstrate that positive feedback enhanced enjoyment as predicted. Further, the fact that participants who received negative feedback had greater endurance than those who received positive or neutral feedback wouldn’t reveal whether positive feedback had an effect on endurance, either positive or negative.
Choice C
Choice C is incorrect because endurance being greater with positive feedback than with neutral feedback would show that positive feedback did have the predicted physical effect (enhancing endurance). Further, reported enjoyment being similar with neutral feedback and negative feedback wouldn’t reveal anything about how enjoyment was affected by positive feedback, and thus wouldn’t show that positive feedback had the predicted psychological effect.